1. Technical Field
The present invention relates to a variable wavelength interference filter, an optical filter device, an optical module, and an electronic apparatus.
2. Related Art
A known variable wavelength interference filter has a pair of reflecting films opposed to each other and varies the distance between the reflecting films to thereby emit light having a predetermined wavelength (see, e.g., JP-A-7-243963).
The variable wavelength interference filter (the optical resonator) described in JP-A-7-243963 is provided with a first substrate and a second substrate opposed to each other, high reflecting films provided to the respective substrates and opposed to each other across an inter-reflecting film gap, and electrodes provided to the respective substrates and opposed to each other. In such a variable wavelength interference filter, by applying a voltage between the electrodes it becomes possible to deform the second substrate to thereby control the inter-reflecting film gap.
In the variable wavelength interference filter according to JP-A-7-243963 described above, the inter-reflecting film gap is controlled with a single electrostatic actuator composed of a pair of electrodes. As a result, there is a problem that a variation in gap amount of the inter-reflecting film gap might occur due to a variation in drive voltage caused by noise or the like which degrades the accuracy of the gap control of the inter-reflecting film gap.